Heat & temps very good. Females usually show sex last, so theres a good chance the ones that havent shown sex yet are females too. Though keep an eye on it ewveryday until it shows sex, just in case.

15/15/15 is good for veg, but now you need to increase the middle one, the "P" in NPK, phosphor. After a few weeks into flowering the P should be roughly double that of the other values (just in general. Read up on that for more details).

I check for purple on the stems - purple and they're underfed (as long as there aren't other circumstances, in which case purple stem can mean other things)

The little burns are hard to see from here, they can get that way just by spilling water/nutes on the leaves. If its only a little it doesn't matter.

All I've got time for right now!